I translated it and they appear to be referring to a Geronimo Stilton book called "Don't binge, Geronimo Stilton!". The book description suggests it's about Geronimo realizes he's become overweight and eating healthy to get back to normal. The second title appears to be a remaster as they both share the same description. I was able to verify that the books showed Geronimo overweight after searching "È ora di... mangiare sano, parola di Geronimo Stilton".
So, the problem is that these books were never translated into English, likely due to being a simple one-shot books about dieting. I couldn't find them on Archive.org or any other library site I use and Wikipedia doesn't appear to mention them. However, I was able to find them for print (€6.50) and e-book (€3.99) on the official website, that's roughly the same amount in $. Does this help at all?